PROJECTSUMMARY/ABSTRACT InfluenzaAvirus(IAV)isamajorcauseofseriousrespiratoryillnessandhasbeenresponsibleforsignificant morbidityandmortalityinhumansworldwide.Thevirusleadstoapproximately200,000hospitalizationsand 36,000deathsannuallyintheU.S.duringnon-pandemicyears.Giventhediseaseseverity,theassociated economiccostsandtherecentappearanceofnovelIAVstrainsand/orvariants,thereisanurgentneedto developnovelandefficacious?universal?vaccinestocombatthissignificantglobalpublichealththreat.Current IAVvaccinesarelimitedbytheneedtoaccountforviralantigendrift/shift,theslowmanufacturingprocess,low tomoderateefficacyrates,andtheinabilitytoinducelungresidentmemoryTandBcellsthatoccurduring naturalIAVinfections.Themostefficaciousuniversalvaccinemayneedtotargetconservedepitopeswithin boththeheadandthestemregionsoftheIAVhemagglutinin(HA)andincludeconservedproteinsthatdriveT cellimmunity.Immunizationsthatgeneratelocaltissue-residentmemoryTandBmemorycellsandsystemic immunityofferthegreatestprotectionagainstfutureIAVencounters.Thus,ourlong-termgoalistodevelopa universalIAVvaccinethatwillinducebroadlyneutralizingantibodies(bnAb)anddurable,IAV-specific,lung- residentTandBcellimmunity,protectagainstgroup1and2IAVstrains,andnotrequireacoldchain.Tothis end,wehavediscoveredanovelimmunogenbasedonequinerecombinantHA3(rHA3)thatelicitsAbin multiplespeciesandprotectsacrossinfluenzagroupsbytargetingboththeHAheadandstemregions.We havealsodevelopedtwopromisingpolymericnanovaccineplatformsthathavebeenshowntoincreaseAb titer,improveTcellimmunity,andprolongantigenreleaseaftervaccination.Oneiscomprisedof biodegradablepolyanhydridenanoparticlesandtheotherisbasedonpentablockcopolymermicelles.Wehave shownthatbothplatformsinducedprotectiveimmunitywithreducedviralloaduponvaccination.TheIAV nanovaccineshowedpromisingefficacyinprotectionagainsthomologousandheterologousIAVinfectionsand inducedTandBcellresponsesinthelungs.Thisproposalwillusethecombinedexpertiseofourteamto determineifananovaccineapproachwillinducebothbnAbanddurable,lung-residentTandBcellimmunity andleadtouniversalprotectionusingthefollowingspecificaims:1)synthesizeandcharacterizerHA3 nanovaccines;?2)establishthesafetyandtoxicologicalprofileofrHA3nanovaccineinmiceandferrets;?3) determinerHA3nanovaccineformulation(s)thatwillelicitthemostappropriateandsustainedresponsetoIAV followingasingle-dosevaccination;?4)designmultivalentrHA3nanovaccinesthatincreasebnAbandCMIto diversestrainsofIAV;?and5)developGLP-compliantprocessforsynthesisofidentifiedleaduniversal nanovaccineandevaluateitsshelflifeindeliverydevices.Theproposedstudieswithtightlyboundmilestones anddecisionpointswillleadtoafinalproductthatwillmeetNIAID?scharacterizationofaprotectiveuniversal IAVvaccineandprovideimportantfirststepsfortranslatingourfindingstohumanclinicaltrials.